Leucine is an amino acid that is much more prevalent in animal-based diets than plant-based diets. The leucine is found in the high concentrations in beef, egg white, isolated soy protein, poultry, fish, spirulina, lamb, parmesan cheese, tofu (0.008) and soy beans.
Aglets are the caps on shoelaces that stop them from unraveling. Our chromosomes have telomeres that perform the same function - they stop our chromosomes from unravelling. The longer they are, the longer the cells survive and the longer we live. An animal-based diet results in shorter telomeres than those on a plant-base diet. Leucine is the amino acid responsible for this.